The Unit is a covert team of U.S. Special Forces operatives who must undertake missions around the world. The latest newcomer is Bob Brown who joins Jonas' team and they set out to rescue an airliner filled with European businessmen who have been hijacked by terrorists. Meanwhile, Bob's wife Kim is struggling with how much control the Unit has on her own personal life.
The team, minus Bob, are in search of a fallen Chinese satellite. This quickly turns into an opportunity to capture one of the world's most wanted terrorists. Meanwhile, Bob is questioned about the Unit's role in the rescue of the hijacked plane. Molly decides to visit the Unit's psychiatrist about the shooting at her home. Kim is frustrating about moving and then comforts a woman who has just learned her husband has died in combat.
Jonas attempts to rescue a group of American missionaries in hiding in Indonesia. However, he soon realizes that the mission is going to require more manpower than he had previously expected.
On the home front, Mack ends up being shot by Bob during a training exercise. Molly, Kim, and Tiffy prepare to host a visiting senator.
The Unit is sent to Los Angeles to protect Mexico's drug minister who has been threatened with assassination and soon his wife and sons are kidnapped. At the base, a former Unit wife makes a return appearance in the hopes of luring the Unit members away. Tiffy is upset when Ryan orders Mack to take time off.
Jonas and the team carry out an assasination of a terrorist in Spain. However, they soon find out that the government called off the mission and will now not protect them in the country which means there only hope is to escape. Back at the base, Molly learns that her daughter Betsy wants to drop out of college and Kim thinks about taking a college course herself.
The Unit must try to get a listening device to an agent inside the Iranian embassy where U.S., Iranian, and Russian diplomats are meeting. Many are speculating that the Russians are attempting to sell the Iranians material to make a nuclear weapon. Meanwhile at the base, Tom tries to end his affair with Tiffy but she won't listen to him and Kim notices Tiffy at a motel room and does not know what she should do.
The crew must fly to Afghanistan to assassinate a high ranking member of the Taliban. However, one of their team helicopters ends up going down in enemy territory, placing the entire crew in jeopardy. Back at the base, Molly confronts a friend and retired Unit veteran about his addiction to painhuggers and Kim ends up getting a job at the local radio station.
The Unit enters the SERE (Survival, Evasion, Resistance Escape) training course and they are lead to believe that they will be guards. The group is soon shocked to discover that they are actually the POWs for an undetermined amount of time.
Jonas and his team must track down surface-to-air missles before they are smuggled out of Brazil after a deal with a drug lord falls through. Jonas gets help from a local boy who informs the team where the SAMs have been taken to be shipped. Meanwhile back on the base, Kim ends up causing even more trouble when she insists that the Family Readiness Group deals with what she deems more serious issues. Also, Williams tries to find a way to tell the woman he wants to marry that he is actually a Unit member and not a clerk on the base like she believes.
After Bob gets his cover blown in Africa, he tells Jonas to cancel a visit a dignitary is taking to the area because of the danger. However, the official refuses and something shocking is quickly learned about why he really wants to go there. Meanwhile, Kim has an encounter while at the radio station and Molly gets offered a real estate opportunity.
Keith Soto returns to the base for a reunion and it's quickly discovered by Jonas and Col. Tom Ryan that he is a newspaper reporter who is writing an article that will expose the Unit. Jonas decides there is only one way to get him to not print the story. Meanwhile, with some help from Tiffy and Kim, Molly tracks down the woman who scammed ,000 of the women's investment fund.
The Unit is called in to consult on a bomb planted in an Atlanta bank, but they soon learn that the bomb might be nuclear. Meanwhile, Bob and Kim decide to take a much needed vacation, but Kim soon discovers that Bob has whisked her away on a mission and wants her to help him out.
The Unit detains a former Yugoslav general who is wanted for war crimes and then allows the U.N. take credit for their capture. However, the criminal escapes U.N. custody and seeks vengeance against Jonas.
On the home front, Tiffy is convinced that Mack has decided to re-enlist with the Unit and considers divorcing him. Kim is the recipient of some disturbing news.